First impressions (the positive):
1. Unboxing the camera, I was confident in the same sturdy build I was accustomed to with all the other Pentax cameras I have owned over the last 12 years, all dSLRs.
2. The shutter is smooth and quiet in operation. I like it, even if the frame rate in FF captures is considerably slower than the APS-Cs and alternate brand FF counterparts.
3. It is not heavy. I was expecting it to be quite noticeably heavier than the K-5. Not so, perhaps it's because I always had the battery grip on, and a couple hundred extra grams on top of 1kg was not enough to be concerned about.
4. It is not large. Camera comparisons are inflating the extra size the K-1 has over the K-5 and K-3. It makes no difference in the bag nor in the hand. It still compares very well against all other FF dSLRs, and even some MILCs.
5. The menus remain straight forward to use, and the addition of the info screen is a nice bonus to access settings quickly.
6. AF is quieter, faster and yet just as accurate. Even the AF-C tracking is improved. Not just marginally.
7. The image quality at the computer editing end is everything I expected it to be. Crisp, clear and there's less editing effort required to get from a RAW to a workable JPEG saved.

Other first impressions (the critical):
1. The VF AF-spot overlay will take some getting used to. I liked the consistency of the *ist D to K-5 VF with its red spot AF confirmation marks. The black-to-red squares occasionally made me doubt whether I got focus right to not.
2. The AF confirmation "beep" sounds more "robotic" than the previous cameras, a minor personal preference I have for the K-5 and previous cameras.
3. The camera makes a whirring sound whilst shooting even when AF is not engaged and the camera is not shooting. Never happened with any previous cameras.
4. The camera's jutting backplate does not sit flush with the battery grip. What's with that? It feels awkward and more clunky to manipulate the camera from landscape to portrait as a result, but I guess it would have made the back LCD less flexible with movement.
5. The third e-dial is one stiff dial!
6. Probably too much redundancy in the access to features, like being able to adjust ISO with the front e-dial, the ISO button near the front e-dial, as well as the function dial that the 3rd e-dial is assigned to.
7. The battery grip's plastic wheel that screws in the grip to the camera body rattles when fiddled with! Don't like that at all. All previous grips I have had, even from the *ist D never had any laxity to them.

Shooting with the camera:
It's all good. Nice VF experience with all my f/2.8 and faster lenses. FA Limited lenses are quite different on the K-1; so much more in the frame. AF locks quickly and I have not had it hunt yet to fix focus. Lots of pixels to play with. Good results so far with ACR and the clarity is just excellent. I have seen Pixel Shift in action, and it's a decent tool to squeeze every bit of detail out of a scene without the need for lossy sharpening in PP. Handheld Pixel Shift is actually going to be handy in more than just the odd occasion, one just has to remember to turn the mode on when it is applicable. It's probably more camera than I'll need, but just like a fine car, we don't get the opportunity much to push it to its limits, but we can appreciate its excellent design, engineering and function nonetheless.

I'm just as late an adopter - got my K-1ii about the same time you did after a lot of going back and forth about the decision. Very pleased with mine and wondering why I waited so long.

Like you I don't have a problem with size or weight. People so often make a big deal about it, but I wonder how often that reaction is really to being all fitted out with both a grip and a new full frame zoom. The weight difference between the K-3 and K-1 bodies hardly registers with me.

Agree about the focus confirmation sound, which I've since turned off in the menu. But I'm not seeing what you describe about the grip being an ill fit - maybe I just don't understand the description. It fits as I'd expect, tightens down snug, nothing wiggles or rattles. Also I personally don't mind the wealth of controls, even if some are redundant between menus and dedicated buttons/wheels. Presumably with growing familiarity it just means I'll learn to do some things faster than in the past.

A big yes about the FA31! I've only shot a little with it so far, but this body definitely brings it into its prime ... so to speak.

I'm not seeing what you describe about the grip being an ill fit - maybe I just don't understand the description. It fits as I'd expect, tightens down snug, nothing wiggles or rattles. Also I personally don't mind the wealth of controls, even if some are redundant between menus and dedicated buttons/wheels. Presumably with growing familiarity it just means I'll learn to do some things faster than in the past.

I was trying to point out the way in which the grip ran flush with the camera body in the K-5/K-3 as opposed to the K-1, where the back of the camera comes out further than the part of the battery grip that it attaches too. The irregularity of this makes it appear to me as an afterthought, however I totally get that it was intended due to the need for space for the screen to be pulled out.

The wealth of controls is fine to me - it was more an observation than a negative point: in general, the more quick controls the merrier, but there is a point at which it can become too much (how many dials do we need to be able to change settings in one or two strokes?)

I'm intrigued about your battery grip. The wheel you use to tighten the grip onto the camera has no looseness to it at all, such that when pushed up or down it does not make a plasticky sound?

Prodding at it now I'll backtrack some on the "wiggle" part. I can make a little play between the knob and the screw, nothing I would notice without going looking for it either by feel or sound.

I also just checked the grip on the K-3ii and found it about the same. If anything the play is less noticeable on the K-1ii because of the same overhang of the screen you mentioned - effectively recessing the knob.

Prodding at it now I'll backtrack some on the "wiggle" part. I can make a little play between the knob and the screw, nothing I would notice without going looking for it either by feel or sound.

I also just checked the grip on the K-3ii and found it about the same. If anything the play is less noticeable on the K-1ii because of the same overhang of the screen you mentioned - effectively recessing the knob.

Okay. I've had grips to the *ist D, K10D, K20D, K-5 and K-5 IIs. None of those grips ever had any play between the wheel and the grip body. All were firmly attached, but the K-1 grip that I have does have some obvious play and I wonder whether that would affect its weather sealing.

All were firmly attached, but the K-1 grip that I have does have some obvious play and I wonder whether that would affect its weather sealing.

That little space between the grip and K1 body has been noticed by a lot of customers who thought it wasn't normal. Doesn't matter, the camera is sealed whether the grip is mounted or not. Eventually, having a small space between the grip and body allow moisture to dry in the contact area. K1 and grip are a please to use. The only downside for me is that the camera with grip doesn't fit in camera bag.

I got my K1ii from black friday. Got a deal I couldn't pass. Timing was a bit earlier than my plan was, as I still have a project going with K5.

K1ii feels like home after K5. In user experience it feels very familiar and easy to use without diving into manuals. Third wheel is great. Size and weight is no issue for me. Love the big bright viewfinder.

For me the upgrade feels more like evolution than revolution. It's a step up in every way, but it's doesn't change the game. You still take the same images and to take the benefit from upgrade your whole process need to be in order. K5 is still a great camera, nice to use and capeable to produce great pictures. K1ii provides even better IQ and user experience.

Doesn't matter, the camera is sealed whether the grip is mounted or not.

Makes sense. The only variable when using the grip is a set of electrical contacts under the rubber plug you remove, and for that part to be properly sealed you just need the grip and body snugged up together well. If there's no play there, it should all be good.

That little space between the grip and K1 body has been noticed by a lot of customers who thought it wasn't normal. Doesn't matter, the camera is sealed whether the grip is mounted or not. Eventually, having a small space between the grip and body allow moisture to dry in the contact area. K1 and grip are a please to use. The only downside for me is that the camera with grip doesn't fit in camera bag.

Moisture in the contacts can't be a good thing. But I gather Ricoh have done their own weather sealing tests on this combination and are happy with the WR rating.
Time will tell.
As for the size of the combination, you might just have to get a slightly bigger bag. I have an over-shoulder camera bag that can fit the K-1+grip+Tamron 28-75 along with the 3 amigos and flash. It's not a big bag, and easily transportable.

I forgot to mention another quirk of design going from the K-5 to a K-1: the LV button has shifted to where the play button was. I keep making the mistake of hitting that LV button when I meant to review the last image I captured. I still think the play button was best off where it was, since the delete button is right next to it.

I forgot to mention another quirk of design going from the K-5 to a K-1: the LV button has shifted to where the play button was. I keep making the mistake of hitting that LV button when I meant to review the last image I captured. I still think the play button was best off where it was, since the delete button is right next to it.

I do the same and I agree. It would be nice, if you could switch the buttons in the settings, if you like.

I hope your K-1 II may provide you with as much joy and pride of ownership as my K-1 does for me.

I found it such a well-rounded, well-made photographic tool that it infused a good amount of fun into my photography again.
Is that silly? Perhaps, but I don't see anything wrong with being excited when somebody else (here the Pentax engineers) excel at their job and gift one with a tool that does much more than simply work.

Originally posted by Ash

3. It is not heavy.

I do find that the K-1 has considerable heft to it. Personally, I find the weight reassuring and believe it helps me to keep the camera steady. However, for someone concerned with weight in the camera bag and/or fatigue when using the camera, I believe it matters that a K-5 (which is not an extreme featherweight) only weighs 73% of the K-1 (batteries included).

With a battery grip attached and loaded with two batteries, my K-1 doubles as a dumbbell.

Originally posted by Ash

5. The third e-dial is one stiff dial!

Yes, I feel it is unreasonably stiff excluding its use as a third dial to be adjusted via the thumb during shooting.
I can operate via the thumb but not really fluently.

Not a big deal for me, as I'm more than fine pressing a button to modify the function of the front/rear dials, but a bit of a lost opportunity.

Not sure my copy has an exceptionally stiff dial as others apparently do use it as a third dial for ISO, for instance, but perhaps they take the camera away from their eye to adjust the ISO setting via the third dial or just force the dial.

Originally posted by Ash

6. Probably too much redundancy in the access to features, like being able to adjust ISO with the front e-dial, the ISO button near the front e-dial, as well as the function dial that the 3rd e-dial is assigned to.

True, that's a lot of options, but on the whole I'd say customisability should be higher not lower. There is a lot one can customise already, but other cameras give one more freedom to reassign the function of buttons, etc. I don't think that flexibility can ever be a negative because if one doesn't need it, one just ignores that particular part in the menu system.

Originally posted by Ash

7. The battery grip's plastic wheel that screws in the grip to the camera body rattles when fiddled with!

My grip wheel does the same. I don't think your's is faulty.

Just to be sure: My grip has no play against the camera body. It's just that the wheel retains a small play even when the grip is tightened. Perhaps the slight wheel play is intentional in order to prevent people from tightening the wheel so much that they cannot remove the grip anymore. As long as your grip sits tight, I wouldn't worry.

My ergonomic niggles would include that the tiny toggle switch above the eight-way (aka "four way") controller is just too small and almost hiding behind the ridge of the eight-way controller. In practice it is not a problem, though, as I very rarely need it and just use the side of my fingernail to actuate it. I also would have preferred the battery grip to replicate the layout of the camera buttons as closely as possible instead of the switcheroo move they made. I could go on a bit, but I realise that the camera was built to a budget under time constraints so not every ideal solution was available to the engineers.

Overall, I think the K-1 (II) is an excellent camera and it enriches my photography experience in a way that a Sony MILC never could.

P.S.: I do hold Sony in high regard and have multiple electronic devices from Sony in my home because of their excellent quality. I just don't like what they think passes as a camera.